This grant proposes to renew the Robert B. Brigham Multipurpose Arthritis and Musculoskeletal Diseases Center (MAC) and supports an Administrative unit, 3 Cores, 3 clinical science grants, and 4 development and feasibility studies. The Cores, Biometry, Morphology and DNA Sequencing, support a variety of biomedical and clinical studies and over 20 investigators. Clinical studies address technology assessment, modification of psychological risk factors to improve outcome, and a primary prevention program and contribute to the basic methodology and understanding of their respective fields. The first study builds on knowledge about the cause and treatment of Lyme Disease and translates this into a primary prevention program aimed at a high-risk population. The trial is the first use of the large simple randomized trial in rheumatic disease. The second study builds on an important finding in SLE, a non-medical modifiable risk factor for disability and disease activity; we propose a controlled evaluation of a psycho-educational intervention to improve self-efficacy in SLE. Our last clinical study examines, in the context of total joint arthroplasty, a fundamental question in the organization of health services: should specialized procedures be regionalized and done only in major centers? The study takes advantage of an emerging technology using administrative data to develop a sample for detailed study of processes and outcomes. The 4 D&F proposals come from some of our most promising junior faculty who have yet to achieve independent NIH funding and examine CD28 independent costimulation of human T-cells in health and disease; pathogenetic mechanisms of a novel T cell in human disease; cellular proteins associated with beta-2 intergrins in lymphocytes; and class II- target transpenics.